The Spain international says he made his choice due to Chelsea's ambitions, their strong squad and manager Jose Mourinho.

The move has angered many Arsenal fans who thought the emotional ties he built up during his eight years at the club meant the Emirates Stadium would be his destination if he ever returned to England.

However, Fabregas wrote in a farewell letter published on Barca's official website that it had been Arsene Wenger's side who decided not to take up their option to re-sign him.

"Firstly I would like to thank everyone at FC Barcelona where I enjoyed three wonderful years," he said. "It was my childhood club and I will always be proud and honoured that I had a chance to play for such a great team. I do feel that I have unfinished business in the Premier League and now is the right time for my return.

"Yes, everyone knows that Arsenal had the first option to sign me. They decided not to take this option and therefore it wasn't meant to be. I wish them well in the future."

The letter also claimed that Fabregas -- who was strongly linked with a move to Manchester United 12 months ago -- had turned down offers from elsewhere to sign for Chelsea.

"I considered all the other offers very carefully and I firmly believe that Chelsea is the best choice," he said. "They match my footballing ambitions with their hunger and desire to win trophies. They have an amazing squad of players and an incredible manager. I am fully committed to this team and I can't wait to start playing.

"It was extremely important to me that this transfer was completed before the World Cup so that my mind will only be focused on hopefully helping my country try to retain the trophy."